7. MACHIMUS 675 



all l)lack) hairs. Anteniiiii brownish black ; two basal joints rather obscured 

 by grey dust ; basal joint with numerous rather short yellow dorsal bristles 

 and with fewer nuich longer black bristles beneath ; second joint with more 

 ec^ual but shorter black bristles ; third joint about as long as the two basal 

 ones together ; style about as long as the third joint and hardly set at an 

 angle to it. 



Thorax yellowish grey, with the blackish brown middle stripe widening 

 anteriorly but steadily contracting after the suture until it becomes rather 

 narrow when it reaches the hindmargin, and the middle stripe has on its 

 broad anterior part a more or less distinct narrow dividing grey middle line ; 

 side-stripes normal (best defined when seen sideways), being interrupted at 

 the suture and extended about half-way from the suture to the hindmargin 

 and then followed by the usual triangular dark spots ; humeral stripes (when 

 seen from in front) sloping inwards on to the disc in front of and inside the 

 front part of the side-stripes, while a slight stripe runs down outside the front 

 part of the side-stripes. Pubescence (as distinguished from strong bristles) 

 represented by small black not dense bristles all over the disc among which 

 sometimes a very few pale ones are intermixed on the anterior part of the 

 middle stripe, though rather short thin pale hairs occur on the humeri, above 

 the wing base, on the ridge of the postalar calli, and across the hindmargin. 

 Bristles mostly black • prsesutural two very strong, with sometimes a smaller 

 third one well anterior ; supra-alar two very strong, placed on the yellowish 

 grey ground colour ; postalar two strong, with sometimes one or two weaker 

 ones near ; dorso-central about nine (7-9), of which about six (4-6) are 

 postsutural and about three (2-5) prsesutural, but the prsesutural ones quickly 

 merge into the short black bristles of the disc though two or three smaller 

 ones may continue to indicate the dorso-central rows ; the dorso-central bristles 

 are rather conspicuous owing to their being placed on the yellowish grey 

 stripes just outside the middle stripe. Pleurae yellowish grey with (in some 

 lights) a dark stripe down just behind the middle of the mesopleurse, and with 

 two dark spots in front ; pubescence mostly pale yellow, long and rather con- 

 spicuous on the prothorax and the space between that and the front coxse, 

 rather long on the upper and back parts of the mesopleurse (sometimes 

 partially or even wholly black), rather slight on the upper part of the sterno- 

 jleurte (where I have seen one rather strong black bristly hair in one specimen), a 

 ittle on the back part of the pteropleuree (where one rather small black bristly 

 'lair occurred in tne specimen just mentioned); metapleurge with numerous 

 pale hairs, and a fan of about eight (3-8) long bristly hairs which are usually 

 yellow but sometimes dark orange or even occasionally mostly black ; 

 hypopleurai with some long pale hairs on the middle part, and a fan of about 

 eight long pale bristly hairs of which the lower four may be weaker than the 

 others. Scutellum grey, bearing rather abundant upright (or slightly 

 forwards-bent) greyish white pubescence in which a few black hairs some- 

 times occur, and with (normally) four long black widely divergent upturned 

 subapical marginal bristles which are slightly bent forwards, but the number 

 and symmetry of these bristles vary so much that they may be three or five 

 in number and consequently more on one side than on the other, but the two 

 nearest the tip are always placed well apart ; metanotum greyish black, bare 

 on the middle but with numerous pale or sometimes black hairs on the back 

 part of the side humps. 



Abdomen when seen from behind very dark but when seen sideways 

 brownish grey, with conspicuous whitish or yellowish grey hindmargins which 

 occupy from a sixth to a quarter of the second to fifth segments, and with 

 similar shimmer on just the sidemargins which widens out a little at the 

 base and end of each segment and which covers the basal segment and the 

 base of the second segment ; eighth segment very short dorsally. 

 Pubescence short black depressed and bristly on the disc of all the 

 segments, but long less bristly and whitish on the sides of the two 

 basal segments and the base of the third, and some short pale incon- 

 spicuous depressed pubescence also occurs on about the front third of the 

 fourth to sixth segments ; basal segment with a long depressed black 

 fringe on its hindmargin and with about five long yellow bristly hairs mixed 

 in the fringe on each side ; second segment with a slight row of shorter 



